Possible Half‐Metallic Ferromagnetism in Rare‐Earth Metals Based Ruthenate Double Perovskites: Ba2RERuO6 (RE = Dy, Tm)

Herein, a systematic mechanism behind long‐range ferromagnetic (FM) ground state is described based on 4 d –4 f interactions demonstrated in strongly correlated Ba 2 DyRuO 6 and Ba 2 TmRuO 6 double‐perovskite (DP) systems. Density functional theory (DFT) + U based possible half‐metallic FM nature of the considered DPs is realized along with integer values of spin magnetic moments (8.0 and 3.0 μ B f.u. −1 , respectively). This robust FM configuration is mainly dependent on Ru 5+ and rare‐earth (RE 3+ ) elements highlighting the importance of B‐site cationic ordering approach used in present study. The optical response of considered rare‐earth ruthenate DPs is also scrutinized, implying their potential usage in optical filter devices. The DFT + U based results are validated via comparing with existing experimental literature. This study suggests Ba 2 DyRuO 6 and Ba 2 TmRuO 6 as a novel addition to the family of half metals and will surely pave the way for materialists to experimentally explore their physical features for spintronic usage.